Disable auto-injection of -D warnings flag in setup-rust-toolchain

Co-authored-by: dontpanic92 <1056013+dontpanic92@users.noreply.github.com>

Author: Copilot

.github/workflows/ci-linux.yml

@@ -20,6 +20,7 @@ jobs:
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: stable
+          rustflags: ''
       - name: Install Deps
         run: |
           wget -qO- https://packages.lunarg.com/lunarg-signing-key-pub.asc | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/lunarg.gpg

.github/workflows/ci-macos.yml

@@ -22,6 +22,7 @@ jobs:
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: stable
+          rustflags: ''
       - name: Install Deps
         run: |
           brew install automake fdk-aac git lame libass libtool libvorbis libvpx opus sdl shtool texi2html theora wget x264 x265 xvid nasm

.github/workflows/ci-windows.yml

@@ -23,6 +23,7 @@ jobs:
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: stable
+          rustflags: ''
       - name: Install Vulkan SDK
         shell: pwsh
         run: |